Question

In an ap the sum of first n terms is 6n-n^2 find it 25th term

Answer 1

$\underline{ \large{ \text{Answer}}} : \\ \\ \text{Given that the sum of the first n terms of an AP is} \\ { \text{S}}_{ \text{n}} = \text{6n} - { \text{n}}^{2} \\ \\ \boxed{ \text{We need to find the 25th term.}} \\ \\ \text{Now, the 25th term be} \\ { \text{t}}_ {25} = { \text{S}}_{25} - { \text{S}}_{24} \\ \\ = \{ 6(25) - {25}^{2} \} - \{ 6(24) - {24}^{2} \} \\ \\ = \{ 150 - 625\} - \{ 144 - 576\} \\ \\ = ( - 475) - ( - 432) \\ \\ = - 475 + 432 \\ \\ = \bold{- 43} \\ \\ \bigstar \: \underline{ \large { \text{MarkAsBrainliest}}} \: \bigstar$